Number Sum Calculator
Sum, count, average, min, and max a list of numbers.
Results
How the number sum calculator works
Paste or type a list of numbers separated by commas, spaces, semicolons, or new lines. The tool parses every token, ignores anything that isn't a valid number (and tells you which tokens were skipped), and instantly computes the sum, count, average (mean), median, minimum, and maximum of the remaining values.
The average is the sum divided by the count: average = sum ÷ count. The median is the middle value once the numbers are sorted (or the average of the two middle values when the count is even) — useful when a few extreme outliers would otherwise skew the average. Negative numbers and decimals are fully supported. Everything runs locally in your browser; nothing you type is uploaded anywhere.
Built and maintained by Meet Shah · Last updated
What this tool is used for
- Totalling a pasted column of figures without opening a spreadsheet.
- Getting a count alongside a sum to check nothing was dropped.
- Finding the minimum and maximum of a set at a glance.
- Adding up an expense list from a pasted receipt.
- Checking a total someone else calculated.
Frequently Asked Questions
- What separators can I paste?
- Any mix of whitespace, commas and semicolons — the split runs on all three, so a spreadsheet column, a CSV fragment and a space-separated line all parse without editing. Newlines and tabs count as whitespace, which means a copied table column works as-is.
- What happens to text that is not a number?
- It is collected and reported back to you rather than silently ignored or coerced to zero. If you paste a column that still has its header, you see exactly which token was skipped. That matters because a zero quietly injected into the list would move both the mean and the minimum without any visible sign.
- Are 'Infinity' or 'NaN' accepted as values?
- No. The check is Number.isFinite, not just 'did it parse', so the strings that JavaScript would happily convert to Infinity or NaN are listed as skipped tokens instead. Without that, a single Infinity would make the sum, the mean and the maximum all Infinity.
- Why show the median next to the average?
- Because they disagree in a way that is informative. For 1, 2, 3, 4, 100 the mean is 22 and the median is 3 — the gap is the outlier announcing itself. Whenever the two are far apart, the mean is being pulled by extremes and the median is the better description of a typical value.
- How accurate is the sum for very large or very precise numbers?
- It uses double-precision floating point like every browser calculation, so integers stay exact to 2⁵³ (about 9 quadrillion) and decimal fractions carry the usual binary rounding — the reason 0.1 + 0.2 shows as 0.30000000000000004 in any JavaScript console. For currency, sum in whole cents to avoid it.
Common errors and gotchas
- Pasting values with thousand separators or currency symbols, which stop parsing as numbers.
- Losing a negative sign, which turns a credit into a charge.
- Including a header row, which is either skipped silently or counted as zero.
- Assuming a locale's decimal mark, where a comma may be a separator or a decimal point.
- Trusting a sum without the count, which is what reveals a dropped line.